Coaster brake



Aug. 27, l940. s. B. KURZINA. JR

COASTER BRAKE 3 Sheets-Sheet 1 Filed latch 28, 1939 gz M V 236 47 46 z3 49 563i 43 5,2 Z5

INVENTOR, BY Siwey J# ATTORNEY.

s. B. KuFzlNA. JR

CQASTER BRAKE 3 Sheets-Sheet 2 Filed latch 28, 1939 INVENTOR. Sfbley/. [dL/"zing, 1/7d ATTORNEY.

Patented Aug. 27, 13940 UNIT E D STAT ES PAT ENT OFF COASTER BRAKE Stanley B. Kurzina, Jr., Elmira, N. Y., assigner toy Bendix Aviation Corporation, South Bend, Intl, a corporation of Delaware Application March 2s, 1939-, serial No. '264,609

The present invention relates to a coaster brake -ior velo'cipedespan'd more particularly to a backpedaling hub brake for bicycles and the like.

It is an obj-ect of the present invention to provide a novel coaster brake incorporating a spiral .brake .member engagea-ble with the interior of the hub. l

It is another obj-ect to provide such a device in whichwthe braking reaction tendsy to assist the w application of the brake by servo action.

`It is a further object to provide such a device in4 which the braking torque is transmitted from the anchored 'en'd'of thefbrake through an anchor sleeve to a torque' arm independently of the im Wheei axle.

It lis another object to provide such a device in ,Which-the free end lof the brake is controlled by `an expander splinedon the anchor sleeve and movable longitudinally by backward motion of fm the 'driving mechanism;

It is 'another object to provide such a device in .which forward rotation is transmitted to the hub through 'a clutch member anchored in the interior ofA the 'hub.

It is another object to provide such a device in 'vv'hicliv the drive crutch member is splined in the hub With freedom for longitudinal movement so as to .relieve the hub bearings of longitudinal pressure therefrom.

30 Itis another object to provide such a device which is efficient in operation and of simple and economical construction.

. Further objects 4and advantages will be apparent. from the following description taken in 3-5 connection With the accompanying drawings in which: i f

Fig. 1 isv a longitudinal section with certain parts broken." away and others shown in elevation, 'of a preferred embodiment of the invention;

v4.0 l Fig.' 2' isa section taken substantially on the -l-ine 2 2 of- Fig. l; f y Fig. 3*' is an vexpanded view in perspective of v"the details o'f the interior structure of Fig. l

Fig, 4 is a view similar to Fig. l of another F45 embodiment of the invention;

' Fig. 5 is a section taken substantially on the line 5--5 of Fig-4; f6 is an expanded 4view in perspective of details ofthe structure: of Fig. Ll, certainV parts being broken away lfor the sake of clarity;

Figl is a similar View of the driving member,

sprocket and associated parts; Y

. Fig. 8: is a view similar' t0 Fig. l 'of a third em` tbodment off'the invention;

Fig, 9 is 'a section taken substantially on the line 8 9 of Fig. 8; A

Fig'. 10 is a section taken substantially on the line Ill--IIJ of Fig. 8'; Aand i 11 is a detail perspectiveof the bearing -5 closure and anti-rattling member illustratedv in Fig. 8.

InFig. -1 of vthe drawings there is illustrated a hub brake lstructure comprising `an axle I on one end of whichA a drivingimember 2 is journalledby alf@ means of an anti-frictionv bearing -3 which is -ad'- instable by means of a Icone bearingmember 'il' threaded onth'eenclof the axle. Driving mem- -ber 2 comprises a .body ,portion 5 which is provided With peripheral splines Iik on which a l5 vsprocket' 'I is non-rotatably mounted. A shoul- .ber and rigidly connected therewith as by Welding or brazing as indicated at I 2f.

An ,anchorv member `inlthe form of a sleeve I3 25 l(Fig.` 3) is loosely mounted on the opposite end yof the axle -I from. the drive member `2.

Anchor sleeve I3 is of non-circularor double-D :section and has mounted on its-outer end -a torque arm I4 j provided with an opening I5 fitting on the anchor 30 `sleeve 4and fixed thereto as by Welding yor brazing.

Abearing cone I-B is loosely mounted on the anchor sleeve I3 addacent the torque arm I4,

p and a similar cone bearing -I'I .is yformed on the driving member 2. A wheel hub I8 is journalled, 35

yon the anchor sleeve and driving member by meansl of anti-friction bearings I9 and 2| cooperating respectively with the conesr I6 and I'I andI with 'bearing cups -22 and 23 formed in the I ends of the hub I8. v.4:0

Spokeflan-ges i4 andy 25- are-mountedon the ends of the hub I8 against :shoulders 26 and v2-I respectively, the flanges-being preferably brazed in place asindicated at` 28 and 29 and being provided with openings -3I for the reception of vvirespolzes.` 45

` A cylindrical .anchor block 32 havinga double- D bore 33 isnon-rotatably mounted on the anchor sleeve I3 adjacent the bearing cone I6. A

spiral brake member 34 vis loosely mounted on the anchor block 32, one end 35 of the brakewo member being in` abutting relationI with a lug 136 welded on or formed integrally with the lanchor bloc-k andpositioned longitudinally by means of aV thrust flange 31 on the anchor block.

y The' end 'of the springis preferably maintainedj in such position by suitable means such as a pin 38 (Fig. 1) traversing an opening 39 (Fig. 3) in the spring and an opening 4I in the anchor' block.

Anchor block 32 is provided with a counterbore 42 in which is piloted an expander sleeve 43 having a double-D bore 44 slidably but non-rotatably mounted on a reduced section 45 of the anchor sleeve I3. A split expanding thimble 46 is mounted on the expander sleeve 43 in abutting relation with the anchor block 32, being non-rotatably connected therewith as by means of a lug 41 engaging in a notch 43 in the anchor block. The external diameter of the thimble 45 is normally the same as that of the anchor block 32 and the free end of the spiral brake member 34 surrounds and bears on said thimble.

An expanding wedge 49 is arranged to enter a tapered recess 5I in the thimble and project therefrom as illustrated in Fig. 1 to engage a shoulder 52 on the end of the expander sleeve 43 whereby longitudinal movement of the expander sleeve to the left in Fig. 1 causes the wedge to enter the recess 5I and expand the thimble.

An actuating member 53 in the form of a nut threaded on the screw shaft II of the driving member is provided with teeth 54 arranged to engage teeth 55 formed on the end of the expander sleeve 43 to prevent relative rotation between the actuating member and expander sleeve when the actuating member is traversed tothe left in Fig. 1. A spring detent member 56 in the form of a cylinder having a flange 51 (Fig. l) clamped into a groove 58 (Fig. 3) in the periphery of the shoulder 52 of the expander sleeve 43, has spring fingers 59 bearing frictionally on the actuating member 53 to retard rotation of the actuating member so as to ensure its traversal upon rotation of the screw shaft by the sprocket 1. Driving means for the wheel hub I8 from the actuating member is provided in the form of a driven clutch member 6I mounted in the hub I8 against a shoulder 62 and rigidly connected therewith as by welding or brazing. Clutch 6I is provided with teeth 63 adapted to engage with teeth 64 on the actuating member 53 when the latter is tra-versed to the right in Fig. 1 by forward rotation of the driving member and screw shaft.

Bearings 3 are preferably enclosed by means of a disc 65 mounted on a reduced portion of -thebearing cone member 4 and maintained thereon by a ring 66 welded or brazed on the cone member 4 and provided with a double-D section to facilitate adjustment of the bea-rings by means of a wrench or Spanner.

Bearings I9 are preferably enclosed by means of a dust cap 61 mounted on the anchor sleeve I3 between the torque arm I4 and bearing cone I6. Bearings 2I are also enclosed by a dust cap or thimble 68 mounted on the driving member 2 and having an inwardly extending ange interposed between the sprocket 'I and shoulder 8.

In the operation of this embodiment of the invention, forward rotation of the sprocket 1 causes rotation of the driving member 2 and screw shaft II, causing traversal of the actuating member 53 to the right in Fig. 1 to engage the driven clutch member 6I, whereupon rotation is transmitted to the hub I8 to propel the vehicle. When rotation of the sprocket 1 is stopped as in coasting, the actuating member 53 is rotated suiciently by the clutch member 6I to cause it to back away and disengage therefrom, whereupon the hub I8 rotates freely.

When the' sprocket 'I is rotated backward, ac-

tuating member 53 is traversed to the left by virtue of the retarding action of detent 56 until it engages the expander sleeve 43. Further backward rotation of the driving member causes the actuating member to move the expander sleeve to the left, causing the Wedge 49 to enter the split thimble 46, causing it to expand and thereby expand the free end of the brake member34 into engagement with the interior of the wheel hub I8. 'Ihe spiral brake member 34 is preferably wound in such a direction that the torque transmitted to the free end of the brake by its frictional engagement in the rotating hub tends to unwrap the brake into more intimate enga-gement with the interior of the hub so as to augment the expanding action of the thimble 46 and cause the brake to be self-energizing. The braking torque is transmitted through the anchored end 35 of the brake member and lug 36 to the anchor block 32 and through the anchor sleeve I3 to the torque arm I4 which is connected to the fra-me of the vehicle, not illustrated. When the backward pressure on the sprocket 1 is released by the operator, the elasticity of the brake member 34 and thimble 46 causes these elements to contract to their original positions, the wedge 49 being projected from the recess 5I in the thimble, and the expander sleeve 43 moving to the right to its normal position. A simple but positive control is thus provided for the brake member which, due to its self-energizing action and full surface contact with the interior of the hub I8, forms a very powerful and effective brake.

In the embodiment of the invention illustrated in Figs. 4 to 7 inclusive, a xed axle member 1I has journalled thereon a driving member 12 by means of anti-friction bearings 13, which driving member is operated by a sprocket 14 non-rotatably connected thereto as by means of splines 15 and held by a split lock ring 16 against a bearing cup member 11 (Figs. 4 and 1) Welded or brazed on the driving member. A screw shaft 18 is piloted in the body of the drive member 12 and xed thereto as by welding or brazing as indicated at 19.

An anchor member in the form of a sleeve 8| of double-D cross-section is mounted on the opposite end of axle 1I and has fixed on its end a torque arm 82 adapted to be connected to the frame of the vehicle to prevent rotation of the anchor sleeve. A thimble 83 (Fig- 6) is mounted on the anchor sleeve 8l adjacent the torque arm 82 and has fixed thereto in any suitable way as by Welding or brazing a bearing cup 84. A wheel hub 85 is journalled in the bearing cups 11 and 84 as by means of anti-friction bearings `86 and 81 in said cups cooperating with cones 88 and 89 formed on the ends of said hub. Spoke flanges 9| and 92 are mounted on the hub preferably by knurling the hub as illustrated in Fig. 6 and forcing the flanges on the hub against shoulders 93 and 94 so positioned that the spoke ilanges cooperate with the bearing cups 11 and 84 to enclose the bearings 86 and 81.

A cylindrical anchor block 95 having a double- D bore 96 is non-rotatably mounted on the anchor sleeve 8| and forms a bearing for a spiral brake member 91, one end 98 of which is anchored by means of a pin 99 against an abutment IIJI rigidly connected to the anchor block 95. shown, abutment IOI is formed as a lug on a ring |02 welded or brazed to the anchor block as indicated at |93 (Fig. 4)

An expanding thimble for the free end of the brake member 91 is provided in the form'of a As here .s

sectional ring '|04 having lugs l|05 entering notches in the anchor member v95 to prevent rotation of the ring and having a tapered bore |01. The sections of the ring |04 are normally held in contracted position by means of a spring member |08' surrounding the same and seated in a `groove |09 in the periphery thereof.

An expander for the ring |04 is provided in the form of a cone member III having a ydouble-D bore I'I2 slidably engaging a reduced portion I I3 of the ranchor sleeve 8| and arranged to enter the tapered bore |01 of the ring |04.

An actuating member I I4 inV the form of a clutch nut is threaded on the screw shaft 18 for automatic traversal thereon into and out of engagement with the expander member IH upon rotation `of the driving member, a spring detent 'I'I5 anchored to the expander member II I being arranged to bear friction'ally on the actuating member I I4 to ensure such traversal.

' A driven clutch member IIB is arranged to be engaged and driven by the lactuating member I I4 upon forward rotation of the driving member. As here illustrated, the driven clutch member I I6 is connected to the hub 85 for rotation therewith by means of radial pins I I1 traversing openings I I8 in said hub. The openings I I8 are preferably somewhat larger than the pins I'I'I so as to allow a slight amount of longitudinal motion of the pins therein. The clutch member H5 is arranged in abutting engagement with the body of the driving member 12. The clamping action of the actuating member I I 4 is thus taken directly by the body of the driving member without transmitting thrust forces to the wheel hub 85 and accordingly to the wheel bearings 86. Pins ||1 are preferably retained in the hub 85 by locating the openings |I8 beneath the spoke flange 9| which accordingly acts as a closure thereof.

In the operation of this embodiment of the invention, forward rotation of sprocket 14 is transmitted to the driving member 12 and screw shaft 18, causing traversal of the actuating member I I4v to the right in Fig. 4, clamping the driven clutch member IIE to the driving member and transmitting rotation through the pins I I1 to the hub 85. When rotation of the Adriving member stops, actuating member |I4 backs away and releases the driven clutch member IIS, allowing the hub 85 to overrun. Backward rotation of the driving vmember causes the actuating member ||4 to en- ,gage the expander cone III and move it to the left in Fig. 4, thus expanding the ring |04 and consequently the free end of the brake member 91 into engagement with the interior of the hub. The brake is thus caused toi unwrap in the hub and engage it with a self-energizing action, the resultant braking torque being transmitted through the abutment |0| and anchor block 95 to the anchor sleeve 8| and torque arm 32. Upon release of the backward pressure on the driving member, the spring ring |08 contracts the expanding ring |04 and the parts return to their idle or coasting positions.

In Figs. 8, 9, and 11l of the drawings an embodiment of the invention is illustrated in which the brake operating mechanism is substantially similar to that illustrated in Fig. l, but novel means are provided for mounting and rotating the hub and spoke flanges. As there illusltrated, an axle |2| has rotatably mounted thereon a 'driving member |22 as by means` of bearings I23.` A screw shaft I is fixed in the body of the driving member as by welding or brazing. An anchor member in the form of a sleeve |24 of 4arm |4I iixed thereto as indicated at |42.

double-D cross-section mounted on the opposite end of the axle, carries an anchor block |25 to which is anchored one end |26 of a spiral brake |21, the free vend of which is expanded by means of a split thimble |28 under the action of a wedge |29 and an expander member |3I, as described in connection with the rst embodiment of the invention.

In the present embodiment of the invention, a cylindrical wheel hub |32 is provided with notches in its ends, and spoke flanges |33 and |34 rare arranged to bear on the ends of the hub and are provided with lugs seating in said notches to nonrotatably connect the flanges to the hub. As shown in Fig. 9, spoke flange |33 has four lugs |35, whereas the end of the hub has eight notches |35. A bearing cone |31 is mounted in the end of the hub |32 and is provided with four radial lugs |38 occupying the notches |36 of the hub vin alternation with the lugs of the spoke flange |33. A bearing cup |39 is mounted on the end of the anchor member |24 adjacent an anchor Antifriction bearings |43 cooperate with the cone |31 and cup |39 to rotatably support the hub |32 on the anchor sleeve |24. Bearing cup |39 cooperates with the spoke flange |33 to enclose bearings I43.

As illustrated in Fig. 10, spoke flange |34 is provided with inwardly extending lugs |44 seated in notches |45 in the end of the hub |32 to nonrotatably connect the spoke flange to the hub. A bearing cup |43 (Fig. 8) is seated within the spoke flange |34. Anti-friction bearings |441 in said cup cooperate with a bearing' cone |43 formed on the driving member |22 to rotatably support the hub |32 on the driving member.

An actuating member in the form of a nut |49 is threaded on the screw shaft |20 and provided with an external conical surface I`5| 'adapted to Vthe hub |32 or bearings |41.

In this embodiment of the invention, a drive sprocket |54 is mounted on the driving memberv |22 by means of splines |55 and a lock ring |56 as in the rst embodiment of the invention. In this embodiment, however, an enclosure thimble |51 for bearings |41 is provided which is also arranged to act as an anti-rattling device for the sprocket |54. For this purpose, thimble |51 is provided with an inwardly extending flange |58 (Fig. 11) in which are formed spring iingers |59. Flange |58 is arranged to engage a shoulder |6| on the driving member |22, while spring iingers |59 bear yieldingly against the sprocket |54 to press it against the lock ring |56 and thereby take up any lost motion which might cause rattling of the sprocket. The spring fingers are preferably cut shorter than the depth of the flange |58 so as to provide notches for the reception of splines |55.

In the operation of this embodiment of the invention, forward rotation of the driving member |22 causes the actuating member |49 to engage the clutch member |52 and clamp it to the driving member for rotation therewith, which rotation is transmitted through lugs |44 of spoke 75 flange |34 to the hub 132. On backward rotation of the driving member E22, the actuating member |49 engages the expander member |31 and causes it to expand the brake 21 as described in connection with the first embodiment of the invention.

Although certain embodiments of the invention have been shown and described in detail, it will be understood that other embodiments are possible and various changes may be made in the design and arrangements of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In a hub brake for velocipedes, a driving member, an anchor member, a wheel hub journalled on the driving and anchor members, a spiral brake member having one end in abutting relation with the anchor member to prevent forward rotation of the brake member, an expansible thimble within the free end of the brake member non-rotatably connected to the anchor member, expanding means therefor including a member slidably but non-rotatably connected to the anchor member, and an actuating member threaded on the driving member and movable by backward rotation of the driving member to engage and actuate the expanding member.

2. In a hub brake for velocipedes, an axle, a driving member journalled on one end thereof, an anchor member mounted on the other end thereof, a wheel hub journalled on the driving and anchor members, a spiral brake member having one end in abutting relation with the anchor member and so arranged that movement of the free end thereof in the direction of forward rotation of the hub causes the brake to expand into engagement with the interior of the hub, an expansible thimble within the free end of the brake member non-rotatably connected to the anchor member, expanding means therefor including a member slidably but non-rotatably connected to the anchor member, and an actuating member threaded on the driving member and movable by backward rotation of the driving member to engage and move the expanding member longitudinally to expand the thimble within the end convolution of the brake member.

3. In a hub brake for velocipedes, a rotatable driving member, a fixed anchor sleeve, a wheel hub journalled on the driving member and anchor sleeve, an anchor block non-rotatably mounted on the anchor sleeve, a spiral brake member mounted on the anchor block and fixed at one end thereto, expanding means for the free end of the brake including a cylindrical member slidably but non-rotatably mounted on the anchor sleeve, a split thimble non-rotatably mounted thereon fitting within the free end of the brake, and means on the slidable member whereby longitudinal movement of the slidable member expands the thimble, and an actuating member movable by backward rotation of the driving member to actuate the slidable member.

4. In a hub brake for velocipedes, a rotatable driving member, a fixed anchor sleeve, a wheel hub journalled on the driving member and anchor sleeve, a cylindrical anchor block non-rotatably mounted on the anchor sleeve, a spiral brake member mounted on the anchor block and fixed at one end thereto, expanding means for the free end of the brake including a member slidably but non-rotatably mounted on the anchor sleeve, a split cylindrical thimble mounted thereon tting Within the free end of the brake and nonrotatably connected to the anchor block, and wedging means on the slidable member whereby longitudinal movement of the slidable member expands the thimble, and an actuating member threaded on the driving member and movable by backward rotation thereof to actuate the slidable member to expand the brake.

5. In a coaster brake, a driving member including a bearing member and a screw shaft, an anchor sleeve having a non-circular cross-section, a fixed torque arm rigidly mounted on the anchor sleeve, a bearing member rotatably mounted on the anchor sleeve adjacent said arm, a wheel hub journalled on the driving member and anchor sleeve by means of said bearings, an anchor block slidably but non-rotatably mounted on the anchor sleeve, an expansible cylindrical brake member mounted on the anchor block and xed at one end thereto', a brake actuating sleeve slidably but non-rotatably mounted on the anchor sleeve, an expansible thimble non-rotatably mounted on the actuating sleeve within the free end of the brake, means whereby longitudinal movement of the actuating sleeve expands the thimble, and a nut on the screw shaft actuated by backward rotation of the shaft to operate the brake actuating sleeve.

6. In a coaster brake, a driving member including a body portion and a screw shalt, said body portion having a shoulder adjacent the end of the screw shaft, a wheel hub journalled on. the driving member, a driven clutch member slidably mounted in the hub member surrounding the screw shaft adjacent said shoulder, keying means extending radially through the hub into the driven clutch member to transmit rotation from the driven clutch member to the hub, a spoke iiange fixed to the hub surrounding and retaining the keying means, and a driving clutch member threaded on the screw shaft arranged to clamp the driven clutch member against the shoulder.

7. In a coaster brake, a driving member including a body portion and a screw shaft, said body portion having a shoulder adjacent the end of the screw shaft, a wheel hub journaled on the driving member, a driven clutch member slidably mounted in the hub member surrounding the screw shaft adjacent said shoulder, a spoke flange mounted on the hub having keying means extending radially through the hub and engaging with the driven clutch member to spline the clutch member to the hub, and a driving clutch member threaded on the screw shaft arranged to clamp the driven clutch member against the shoulder.

8. In a coaster brake for bicycles, a hub, an axle, a driving member journalled thereon, an overrunning clutch between the driving member and hub, brake means for the hub actuated by reverse rotation of the driving member, a sprocket mounted on the driving member, said sprocket having spaced keyways in its bore, the driving member having peripheral lugs fitting said keyways, said lugs having shoulders forming abutments for the sprocket, and a locking ring seated in the periphery of the driving member confining the sprocket thereon.

9. In a coaster brake for bicycles, a hub, an axle, a driving member journalled thereon, an overrunning clutch between the driving member and hub, brake means for the hub actuated by reverse rotation of the driving member, a sprocket mounted on the driving member, said sprocket having spaced keyways in its bore, the driving member having peripheral lugs fitting said key- 1| Ways, said lugs having shoulders forming abutments for the sprocket, a sealing ring on the driving member, notched to accommodate the lugs and bearing against the shoulders, said member having a peripheral groove, and a locking ring seated in the groove bearing against the sprocket.

10. In a driving hub for bicycles, an axle, a driving member journalled thereon, a sprocket mounted on the driving member, said sprocket lhaving spaced keyways in its bore, the driving member having peripheral lugs tting said keyways, said lugs having shoulders forming abutments for the sprocket, a sealing ring on the driving member interposed between the sprocket and shoulders, notched to accommodate the lugs and having spring arms bearing against the sprocket, and a locking ring on the driving member confining the sprocket thereon against the pressure of said arms.

l1. In a bicycle hub, an axle, a bearing cup lxed thereon, a hub shell extending within the cup and having radial notches in one end, a bearing cone seated in said end of the hub shell having radial lugs in said notches, and antifriction bearings interposed between the cup and cone.

l2. In a bicycle hub, an axle, a bearing cup xed thereon, a cylindrical hub shell having one end located within the cup', and having radial notches in said end, a bearing cone seated in said end of the hubshell having radial lugs in certain of said notches, a spoke flange seated on` said end of the hub shell and having inwardly directed lugs seated in the remainder of said notches, and anti-friction bearings interposed between the cup and cone.

13. In a bicycle hub, a cylindrical hub shell having radial notches in one end, a dished spoke flange seated on said end of the shell with lugs in said notches, a bearing cup in the spoke flange, and a driving member extending into the hub shell and journalled in the bearing cup.

lll. In a bicycle hub, a cylindrical huby shell having radial notches in one end, a dished spoke flange seated on said end of the shell with lugs extending inwardly through said notches, a bearing cup in the spoke ilange, a driving member extending into the hub shell and journalled in the bearing cup, a driven clutch member in said end of the shell having peripheral notches to receive the inner ends of said lugs, and means including a driving clutch member threaded on the driving member for clamping the driven clutch member to the driving member.

STANLEY B. KURZINA, JR. 

